Abstract: Novel geometries for high intensity discharge solenoidal electric field lamps are disclosed providing good coupling between the magnetic fields within the ferrite and the plasma discharge. In addition, the geometries provide for good heat sinking and cooling capabilities as well as escape of most of the generated light. In accordance with one embodiment of the present invention, a plurality of toroidal shaped ferrite cores are arranged about the high intensity discharge tube, the tube being threaded through the holes in the toroidal ferrite cores. In accordance with another embodiment of the present invention, a bundle of ferrite rods is disposed through the hole of a toroidal shaped discharge tube, the packing density of the ferrite rods in the bundle being less than one hundred percent efficient whereby channels for cooling air are formed.

Abstract: A low pressure sodium vapor lamp including a sodium vapor discharge tube and a light reflector partially surrounding the discharge tube and defining a light transmission aperture for desired directional light output. The light reflector is in tangential contact with the discharge tube on the surface thereof opposite to the light aperture. The contact between discharge tube and light reflector provides a thermal coupling for heat conduction from the discharge tube. The area of this thermal coupling thus becomes the coolest portion of the discharge tube, the "cold spot" of the lamp where excess sodium is condensed.

Abstract: HID lamp has a spring-loaded safety switch positioned between the outer protective envelope and the arc tube and electrically connected in series with one of the lamp electrodes. When the lamp is operating normally, the safety switch is maintained in the closed position, but if the outer envelope is accidentally broken, the switch automatically opens to break the lamp energizing circuit and render the lamp inoperative.

Abstract: HID lamp has resilient safety switch positioned proximate the inner surface of the dome portion of the protective outer envelope in contact with an extremity of a resilient leaf-spring support portion of the arc tube frame, to maintain the switch in a closed position. When the envelope is shattered, the normally closed switch will open to break the electrical path to the arc tube, thereby rendering the lamp inoperative.

Abstract: The adherence of an optically reflective coating of refractory metal oxide particles such as ZrO.sub.2 or Al.sub.2 O.sub.3 on a fused silica discharge tube surface is improved severalfold by an adhesion layer consisting of colloidal aluminum oxide and boric oxide powders. The adhesion layer may be first applied and dried, the refractory metal oxide coating then applied, and the quartz tube then heated to a temperature greater than 460.degree. C., the melting point of boric oxide. The refractory metal oxide particles may also be applied admixed with the colloidal aluminum oxide and the boric oxide. The improved coating strength permits the use of a thicker layer of refractory metal oxide for higher optical and thermal reflection.

Abstract: The invention relates to a gas and/or vapor discharge lamp which is provided with a discharge tube and an outer bulb which envelops this tube, whilst the heat insulation in the space between the discharge tube and the outer bulb can be changed.According to the invention the heat insulation is changed by means of a reversible hydrogen getter which is located in the space between the outer bulb and the discharge tube. In this way it is obtained that the lamp can either be operated without a stabilizing ballast or that it is less sensitive to variations in the mains supply.

Abstract: A device for generating a high level electron current pulse includes a housing whose interior can be evacuated from outside the housing, a cathode electrode located in the housing and arranged to be connected to a high voltage generator, an anode electrode disposed in the housing in facing relation to the cathode electrode, the anode electrode having an opening aligned with the electron emission portion of the cathode electrode and being provided with a grid which covers this opening and which presents a high electron transmission level, the grid defining a plane with one face of the anode electrode, and the walls of the housing defining an annular space filled with a solution whose resistivity is a function of its concentration to give these walls a variable electrical resistance which can be adjusted to match the impedance of the cathode electrode - anode electrode system to that of the high voltage generator.

Abstract: A laser diode is provided with a casing that encloses a light-emitting crystal. The casing includes a transparent member through which the light passes. A portion of the diode is positioned within a holder and means is provided for cooling the diode. To reduce condensation of moisture which is present within the holder, upon the transparent member, a sleeve formed of a thermally high conductor material such as copper is placed about the casing with close physical contact therebetween.